Bridge Too Far: AFX Loses $24M While Arbitrum's Native Bridge Sips Tea Unbothered

A crosschain bridge operated by AFX, a decentralized perpetual exchange on Arbitrum, was exploited on Wednesday for $24.15 million, according to onchain investigator Lookonchain. The attacker bridged 24.15 million USDC to Ethereum and used the proceeds to purchase 12,467 ETH at an average price of $1,937.

Blockaid, a blockchain security firm, said it detected the exploit at 9:30 pm UTC, identifying the targeted bridge as one operated by AFX. The firm flagged the suspicious activity on Wednesday as the transactions moved through the crosschain infrastructure.

Offchain Labs co-founder Stephen Goldfeder addressed the incident on X, distinguishing between the compromised protocol and the Arbitrum native bridge. "We're aware of a report of a bridge hack on Arbitrum and are investigating. We can confirm that the transaction in question originated from a third-party protocol, and the Arbitrum native bridge has not been hacked or exploited in any way," Goldfeder said.

Arbitrum itself was not impacted by the exploit, which targeted a third-party protocol rather than the network's native bridging infrastructure. AFX, the affected exchange, has not yet published a public postmortem on the incident.

Lookonchain, which tracks significant onchain movements, traced the stolen USDC as it crossed to Ethereum and was converted into $ETH. The firm reported the specific transaction details, including the total amount bridged and the average acquisition price for the $ETH purchased with the proceeds.

This is a developing story and more information will be added as it becomes available.